Encoder signal processing device, printer, printer-equipped imaging apparatus, and encoder signal processing method

ABSTRACT

An encoder signal processing device, a printer, a printer-equipped imaging apparatus, and an encoder signal processing method that can remove the effect of a noise signal mixed with an encoder signal and favorably deal with a case where an original pulse signal is lost from the encoder signal are provided. An effective detection period setting unit  523  sets an effective detection period for detecting a subsequent pulse signal, each time a pulse signal detection unit  522  detects a pulse signal from an encoder signal. The pulse signal detection unit  522  detects the pulse signal only within the set effective detection period. In a case where the pulse signal detection unit  522  does not detect the pulse signal within the effective detection period, a pulse signal generation unit  524  generates the pulse signal after the effective detection period.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Continuation of PCT International Application No.PCT/JP2017/007615 filed on Feb. 28, 2017, which claims priority under 35U.S.C § 119(a) to Japanese Patent Application No. 2016-135047 filed onJul. 7, 2016. Each of the above application(s) is hereby expresslyincorporated by reference, in its entirety, into the presentapplication.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The present invention relates to an encoder signal processing device, aprinter, a printer-equipped imaging apparatus, and an encoder signalprocessing method and particularly, to a technology for favorablyacquiring a pulse signal from an encoder signal output from an encoder.

2. Description of the Related Art

Generally, an encoder (optical rotary encoder) is widely used fordetecting the amount of rotation or a rotational speed of an electricmotor, the amount of movement or a movement speed of a transported bodytransported by a transport device driven by the electric motor, or thelike.

Such a type of encoder irradiates a circular plate (rotating slit plate)disposed on a rotating shaft of the electric motor or a shaft to whichrotational driving power of the electric motor is transmitted, withlight from one side using a light emitting element such as a lightemitting diode or the like. Transmitted light after the light istransmitted through the circular plate, or reflective light from thecircular plate is received by a light receiving element such as aphotodiode, and an encoder signal that includes a pulse signal having acycle corresponding to a rotational speed of the circular plate isoutput. The encoder signal is acquired by amplifying an output signal ofthe light receiving element and shaping the waveform of the outputsignal to a rectangular wave using a waveform shaping circuit.

In a case where noise is mixed with the encoder signal, a problem arisesin that the rotational speed and/or a rotational position of thecircular plate is erroneously detected.

In the related art, as a measure for noise in the encoder signal, it isknown that a high frequency noise signal is removed by an analoglow-pass filter or a digital low-pass filter (JP2003-148997A). A devicedisclosed in JP2003-148997A detects the magnitude of noise as a pulsewidth and sets the number of filter stages of the digital filtercorresponding to the magnitude of noise depending on an ambient noiselevel.

SUMMARY OF THE INVENTION

Multiple fine slits (for example, slits having a width of 100 μm) areformed around the rotating slit plate of the encoder. Dust having a sizegreater than or equal to the slit width may be attached to the slit ofthe rotating slit plate of the encoder at the time of loading an instantfilm pack. In this case, a problem arises in that the pulse signal(rectangular wave signal) corresponding to the slit to which dust isattached is not output (lost) from the encoder.

While the device disclosed in JP2003-148997A can remove the noise signalmixed with the encoder signal, a problem arises in that the lost pulsesignal cannot be detected in a case where the original pulse signal tobe included in the encoder signal is lost by attachment of dust or thelike.

The present invention is conceived in view of such matters. An object ofthe present invention is to provide an encoder signal processing device,a printer, a printer-equipped imaging apparatus, and an encoder signalprocessing method that can remove the effect of a noise signal mixedwith an encoder signal and favorably deal with a case where an originalpulse signal is lost from the encoder signal.

In order to achieve the above object, an encoder signal processingdevice according to one aspect of the present invention comprises anencoder signal input unit that inputs an encoder signal including apulse signal having a cycle corresponding to a transport speed of atransported body from an encoder detecting the transport speed of thetransported body, an effective detection period setting unit that setsan effective detection period for detecting a subsequent pulse signaleach time the pulse signal is detected from the input encoder signal, apulse signal detection unit that detects the pulse signal from theencoder signal only within the set effective detection period, and apulse signal generation unit that generates the pulse signal after theeffective detection period in a case where the pulse signal is notdetected from the encoder signal within the effective detection period.

According to one aspect of the present invention, the effectivedetection period for detecting the subsequent pulse signal is set, eachtime the pulse signal is detected from the input encoder signal.Accordingly, even in a case where a noise signal is mixed in a periodother than the effective detection period, the noise signal is noterroneously detected, and the noise signal can be removed. In addition,in a case where the pulse signal is not detected from the encoder signalwithin the effective detection period, the pulse signal is generatedafter the effective detection period. Thus, even in a case where theoriginal pulse signal is lost from the encoder signal, the lost pulsesignal can be supplemented.

In the encoder signal processing device according to another aspect ofthe present invention, it is preferable that the effective detectionperiod setting unit sets the effective detection period based on a cycleof a plurality of the most recent pulse signals detected by the pulsesignal detection unit and a width of change in the transport speed ofthe transported body. In a case where the transport speed of thetransported body changes, the cycle of the pulse signal detected fromthe encoder signal also changes. Accordingly, the set effectivedetection period is set based on the cycle of the pulse signalcorresponding to the current transport speed of the transported bodyacquired from the plurality of most recent pulse signals and the widthof change acquired by predicting a change in the transport speed of thetransported body.

In the encoder signal processing device according to still anotheraspect of the present invention, it is preferable that the plurality ofmost recent pulse signals are three or more pulse signals, and the cycleof the pulse signal is a cycle of an average of two or more cyclesacquired from the three or more pulse signals.

In the encoder signal processing device according to still anotheraspect of the present invention, it is preferable that the pulse signaldetection unit detects only initial one pulse signal within theeffective detection period. In a case where the noise signal is mixed inthe effective detection period, two or more pulse signals may bedetected. In this case, only the initial one pulse signal is detected.While a case where the initial one pulse signal is the noise signal isconsidered, the noise signal in this case and the original pulse signalhas a difference within the width of change in transport speed. Thus,problems are not caused in a process in a subsequent stage.

It is preferable that the encoder signal processing device according tostill another aspect of the present invention further comprises a delaycircuit that outputs the pulse signal detected by the pulse signaldetection unit by delaying the pulse signal by a certain time period.

The reason is that in a case where the pulse signal is generated afterthe effective detection period, the generated pulse signal and the pulsesignal to be detected by the pulse signal detection unit are notsignificantly shifted from each other.

In the encoder signal processing device according to still anotheraspect of the present invention, it is preferable that the certain timeperiod is a time period that corresponds to the effective detectionperiod.

A printer according to still another aspect of the present inventioncomprises the encoder signal processing device, an image data input unitthat inputs image data, a line head that is driven based on the inputimage data, a transport unit that transports a printing medium as thetransported body in a direction orthogonal to a longitudinal directionof the line head, the encoder that outputs the encoder signal includinga pulse signal having a cycle corresponding to a transport speed of theprinting medium transported by the transport unit, and a control unitthat controls a printing timing of the line head for a line image insynchronization with the pulse signal detected by the pulse signaldetection unit and the pulse signal generated by the pulse signalgeneration unit. In a case where the line head is driven insynchronization with the pulse signal and the noise signal, whitestreaks accompanied by mixing of the noise signal occur in the printingmedium. However, by removing the noise signal, the occurrence of whitestreaks can be prevented. In addition, in a case where the pulse signalis lost, black streaks occur in the printing medium. However, since thepulse signal is generated in a case where the pulse signal is lost,black streaks can be removed.

In the printer according to still another aspect of the presentinvention, it is preferable that the effective detection period settingunit sets the effective detection period based on a cycle of a pluralityof the pulse signals detected by the pulse signal detection unit beforethe printing timing of the line head for the line image and a width ofchange in the transport speed of the printing medium.

In the printer according to still another aspect of the presentinvention, it is preferable that the plurality of pulse signals beforethe printing timing are three or more pulse signals, and the cycle ofthe pulse signal is a cycle of an average of two or more cycles acquiredfrom the three or more pulse signals.

In the printer according to still another aspect of the presentinvention, it is preferable that the transport unit includes a capstanroller and a pinch roller that pinch and transport the printing medium,and the encoder is a rotary encoder that includes a circular platearranged coaxially with an axis of the capstan roller and outputs theencoder signal including a pulse signal having a cycle corresponding toa rotational speed of the circular plate.

In the printer according to still another aspect of the presentinvention, it is preferable that the printing medium is an instant filmthat senses light depending on an amount of light, and the control unitcontrols an amount of light emission emitted from the line head based onthe input image data and causes the instant film to sense light.

A printer-equipped imaging apparatus according to still another aspectof the present invention comprises the printer, and an imaging unit thatfunctions as the image data input unit.

An encoder signal processing method according to still another aspect ofthe present invention comprises a step of inputting an encoder signalincluding a pulse signal having a cycle corresponding to a transportspeed of a transported body from an encoder detecting the transportspeed of the transported body, a step of setting an effective detectionperiod for detecting a subsequent pulse signal each time the pulsesignal is detected from the input encoder signal, a step of detectingthe pulse signal from the encoder signal only within the set effectivedetection period, and a step of generating the pulse signal after theeffective detection period in a case where the pulse signal is notdetected from the encoder signal within the effective detection period.

According to the present invention, the effect of the noise signal mixedwith the encoder signal can be removed, and it is possible to favorablydeal with a case where the original pulse signal is lost from theencoder signal.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exterior view illustrating a configuration of a printingsystem including a printer according to an embodiment of the presentinvention.

FIG. 2 is a view illustrating a state where an instant film pack isloaded into the printer.

FIG. 3 is an exploded perspective view of the instant film pack.

FIG. 4 is a plan view of an instant film seen from a light exposuresurface side.

FIG. 5 is a plan view of the instant film seen from an observationsurface side.

FIG. 6 is a perspective view illustrating a transport mechanism for theinstant film and a film cover.

FIG. 7 is a plan view illustrating the transport mechanism for theinstant film and the film cover.

FIG. 8 is a front view of a main part of the transport mechanism for theinstant film and the film cover.

FIG. 9 is a block diagram illustrating an embodiment of the printeraccording to the embodiment of the present invention.

FIG. 10 is a view illustrating a state where the instant film and thefilm cover are transported.

FIG. 11 is another view illustrating a state where the instant film andthe film cover are transported.

FIG. 12 is still another view illustrating a state where the instantfilm and the film cover are transported.

FIG. 13 is a block diagram illustrating a first embodiment of an encodersignal processing device disposed in the printer.

FIG. 14 is a view illustrating a signal waveform of each unit used fordescribing a processing content of the encoder signal processing device.

FIG. 15 is a graph illustrating one example of a transport speed of theinstant film.

FIG. 16 is a partial enlarged view of a graph illustrating the transportspeed of the instant film illustrated in FIG. 15.

FIG. 17 is a block diagram illustrating a second embodiment of anencoder signal processing device in the printer.

FIG. 18 is a view illustrating correction (density correction) of alight exposure timing and the amount of light emission of a lightexposure head that performs light exposure in synchronization with apulse signal of an encoder signal.

FIG. 19 is a perspective view illustrating a printer-equipped camera.

FIG. 20 is a block diagram illustrating a configuration of theprinter-equipped camera.

FIG. 21 is a flowchart illustrating a printing method including anencoder signal processing method.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereinafter, embodiments of an encoder signal processing device, aprinter, a printer-equipped imaging apparatus, and an encoder signalprocessing method according to the present invention will be describedwith reference to the appended drawings.

[Printer]

FIG. 1 is an exterior view illustrating a configuration of a printingsystem including the printer according to an embodiment of the presentinvention. A printing system 100 illustrated in FIG. 1 is configuredwith a smartphone 200 and a printer 300.

The smartphone 200 includes a capturing optical system and a wirelesscommunication unit, not illustrated, and transmits image data of animage captured through the capturing optical system by a user and aprinting instruction for the image data to the printer 300 through thewireless communication unit. At this point, data of a so-called template(text, numbers, symbols, illustrations, and the like) may also betransmitted together and may be printed along with the image. Asmartphone that is generally used can be used as the smartphone 200,provided that the smartphone is of a type that can perform capturing andwireless communication. Management and transmission of data such as theimage data, the printing instruction, and the template may be performedby installing a dedicated application on the smartphone 200.

The printer 300 can perform wireless communication and performs printingon an instant film 10, described below, as a printing medium through awireless communication unit 75 (refer to FIG. 9; image data input unit)using the image data, the template (in a case where the template istransmitted from the smartphone 200), and the printing instructionreceived from the smartphone 200. The instant film 10 after printing isdischarged from a film discharge port 311 that is disposed in an endportion of the printer 300. The printer 300 includes an operation unitand a display unit, not illustrated.

A device that transmits the image data to the printer 300 is not limitedto the smartphone 200 and may be a digital camera, a portableinformation terminal, a tablet terminal, or the like that has a wirelesscommunication function. In addition, the printer 300 is not limited tothe case of receiving the image data by wireless communication and mayreceive the image data by a communication cable or through a recordingmedium such as a memory card.

<Loading of Instant Film Pack>

FIG. 2 is a view illustrating a state where an instant film pack 1 isloaded into the printer 300. A loading chamber 315 is disposed in theprinter 300. The instant film pack 1 is loaded into the loading chamber315. A lid member 302 that is openable and closable is disposed in theloading chamber 315. The user closes the lid member 302 after loadingthe instant film pack 1. An uplifting member 304 that is biased by aspring, not illustrated, is disposed in the lid member 302. In a casewhere the lid member 302 is closed after the instant film pack 1 isloaded into the loading chamber 315, the uplifting member 304 isinserted into an uplifting member insertion part 33 disposed on the rearsurface of the instant film pack 1 and uplifts a light shielding sheet50 (refer to FIG. 3) to a front surface side (an opposite side of theuplifting member insertion part 33 from an opening surface), and theinstant film 10 is pressed to an inner surface of a case 20.

<Configuration of Instant Film Pack>

FIG. 3 is an exploded perspective view of the instant film pack 1. Theinstant film pack 1 is configured to comprise the instant film 10, thecase 20 (refer to FIG. 2) that accommodates the instant film 10, and thelight shielding sheet 50, and a film cover 60. The case 20 is configuredwith a case main body 22 and a case lid 24 that covers the rear surfaceof the case main body 22.

<Case Main Body>

The case main body 22 has a flat box shape of which a rear surfaceportion is open. The case main body 22 comprises a light exposureopening portion 26 for exposing a light exposure area of the instantfilm 10, a discharge port 28 for discharging the instant film 10, a caseflap material 29 for shielding the discharge port 28 from light, and aclaw opening portion 32 for inserting a claw member 72 (refer to FIG. 9to FIG. 12). The light exposure opening portion 26 has a shape thatcorresponds to the shape of a light exposure portion 12 (refer to FIG.4) of the instant film 10. The light exposure opening portion 26 isarranged at a position where the light exposure portion 12 of theinstant film 10 accommodated in the case 20 is exposed.

The discharge port 28 is disposed in a top surface portion of the casemain body 22 and has a slit shape of a size through which the instantfilm 10 can pass. The discharge port 28 is arranged at a position wherethe instant film 10 that is positioned in the uppermost part in a stackdirection can be discharged.

The case flap material 29 is configured with a film piece having arectangular shape and blocks the discharge port 28 in an openable andclosable manner by bonding the case flap material 29 to the case mainbody 22 along a long edge on one side.

A front surface part 22 a and a bottom surface portion 22 c of the casemain body 22 comprise the claw opening portion 32 as illustrated in FIG.6. The claw opening portion 32 has a slit shape and is linearly arrangedin the front surface part 22 a with the bottom surface portion 22 c as astart point. The bottom surface portion 22 c of the case main body 22comprises an entrance portion 32 a that has a notch shape andconstitutes a part of the claw opening portion 32 as illustrated in FIG.6. The front surface part 22 a of the case main body 22 comprises apassage portion 32 b that has a slit shape and constitutes a part of theclaw opening portion 32. The passage portion 32 b is linearly arrangedin a transport direction F of the instant film 10. The end point of thepassage portion 32 b is the light exposure opening portion 26. That is,the claw opening portion 32 is arranged in a form of linearly connectingthe bottom surface portion 22 c and the light exposure opening portion26 of the case main body 22. The width of the claw opening portion 32 isset to a width through which the claw member 72 can be inserted.

<Case Lid>

The case lid 24 has a rectangular plate shape and is mounted on the rearsurface portion of the case main body 22 to cover the open rear surfaceof the case main body 22. The case lid 24 comprises a pair of upliftingmember insertion parts 33, a pair of film support units 31, and a pairof light shielding sheet attaching units 42. The uplifting memberinsertion parts 33 are opening portions for inserting the upliftingmember 304 (refer to FIG. 2). The film support units 31 are supportunits that support the instant film pack 1 accommodated in the case 20.The film support units 31 are configured with thin plates having an arcshape and are arranged inside the case lid 24 along the long edges ofthe case lid 24 on both sides. The instant film 10 accommodated in thecase 20 is supported in a convex shape by the film support units 31. Thelight shielding sheet attaching units 42 are attaching units for thelight shielding sheet 50. The light shielding sheet attaching units 42are configured with pins having a cylindrical shape and are arranged inparallel in a central part of the case lid 24.

<Light Shielding Sheet>

The light shielding sheet 50 supports the instant film 10 and shieldsthe instant film 10 from light in the case 20. The light shielding sheet50 is configured by combining a first light shielding sheet 53functioning as a plate spring and a second light shielding sheet 54functioning as a support plate. The light shielding sheet 50 into whichthe first light shielding sheet 53 and the second light shielding sheet54 are integrated is attached to the case lid 24 by fitting a fixedportion 53 b of the first light shielding sheet 53 with the lightshielding sheet attaching units 42 of the case lid 24 and bonding thefitted part. The light shielding sheet 50 attached to the case lid 24 isarranged between the pair of film support units 31.

As described above, in a case where the lid member 302 is closed afterthe instant film pack 1 is loaded into the loading chamber 315, theuplifting member 304 is inserted into the uplifting member insertionparts 33. The light shielding sheet 50 is pressed by the upliftingmember 304 inserted into the uplifting member insertion parts 33, andthe instant film 10 is pressed to the inner surface of the case 20. Atthis point, the first light shielding sheet 53 elastically deforms andelastically presses the instant film 10 to the inner surface of the case20.

<Film Cover>

The film cover 60 shields light from the light exposure opening portion26. As illustrated in FIG. 3, the film cover 60 is accommodated in thecase 20 such that the film cover 60 is arranged in an overlapping mannerwith the uppermost part of the stacked instant film 10. The film cover60 comprises a notch portion 62 and a film cover skirt material 64. Thenotch portion 62 has a slit shape and is comprised in a proximal endportion of the film cover 60. The notch portion 62 is arranged in a feeddirection of the film cover 60. A position at which the notch portion 62is arranged is set to the same position as the claw opening portion 32.Accordingly, in a case where the film cover 60 is accommodated in thecase 20, the notch portion 62 is arranged such that the notch portion 62leads to the claw opening portion 32. The notch portion 62 has the samewidth as the claw opening portion 32. The “same width” includes almostthe same width.

The film cover skirt material 64 is one example of a light shieldingmember and is attached to the film cover 60 to shield light from theclaw opening portion 32 and the notch portion 62. The film cover skirtmaterial 64 is configured with a sheet piece having a rectangular shape.The film cover skirt material 64 is attached to a rear surface portionof the film cover 60 and blocks the notch portion 62. At this point, apart of the film cover skirt material 64 is attached such that the partprotrudes from the film cover 60. The protruding part functions as askirt portion for blocking the entrance portion 32 a of the claw openingportion 32. In a case where the film cover 60 is accommodated in thecase 20, the entrance portion 32 a of the claw opening portion 32 isblocked by the skirt portion, and light from the entrance portion 32 ais shielded.

The film cover skirt material 64 is attached to the film cover 60 bybonding. In addition, the film cover 60 mounted on the case 20 is fixedby bonding the skirt portion of the film cover skirt material 64 to theinner surface of the case 20. In a case where the claw member 72 startstransporting the film cover 60, the film cover skirt material 64 movesalong with the film cover 60 and is discharged from the discharge port28.

<Instant Film>

The instant film 10 is a well-known self-developing type instant filmand has a rectangular card shape. As illustrated in FIG. 4 and FIG. 5,the instant film 10 is configured such that a surface on one side is alight exposure surface (photosensitive sheet) 10 a, and a surface on theother side is an observation surface (cover sheet) 10 b. The instantfilm 10 in the present example is a positive photosensitizer such thatthe density of each of red, green, and blue is increased as the amountof incident light of three primary colors (red, green, and blue) isincreased.

FIG. 4 is a plan view of the instant film seen from the light exposuresurface 10 a side. In the drawing, a direction that is indicated usingan arrow is a feed direction (transport direction F) of the instant film10. The feed direction means a direction in which the instant film 10 isused. In a case where the instant film 10 is accommodated in the case20, the feed direction of the instant film 10 is a discharge directionof the instant film 10. The light exposure surface 10 a comprises thelight exposure portion 12, a pod portion 14, and a trap portion 16. Thelight exposure portion 12 is a light exposure area and is arrangedbetween the pod portion 14 and the trap portion 16 as an area having arectangular shape. The pod portion 14 is arranged on a distal end sidein the feed direction of the instant film 10. The pod portion 14incorporates a developing treatment liquid pod 14 a that contains adeveloping treatment liquid. The trap portion 16 is arranged on aproximal end side in the feed direction of the instant film 10. The trapportion 16 incorporates an absorbing material 16 a.

FIG. 5 is a plan view of the instant film seen from the observationsurface 10 b side. In FIG. 5, a direction that is indicated using anarrow is the feed direction (transport direction F) of the instant film10. The observation surface 10 b comprises an observation portion 18that is an observation area of the captured image. The observationportion 18 is arranged in correspondence with the light exposure portion12 on the light exposure surface side.

The instant film 10 is subjected to a developing treatment by spreadingthe developing treatment liquid in the pod portion 14 to the lightexposure portion 12 after light exposure. By passing the instant film 10between a pair of spread rollers 40 (refer to FIG. 6 to FIG. 8), thedeveloping treatment liquid in the pod portion 14 is squeezed and isspread to the light exposure portion 12. At this point, the remainingdeveloping treatment liquid is trapped by the trap portion 16.

<Assembly of Instant Film Pack>

The instant film pack 1 is assembled by accommodating the film cover 60and the instant film 10 in the case main body 22 and closing the rearsurface of the case main body 22 with the case lid 24. At this point,first, the film cover 60 is accommodated in the case main body 22. Theskirt portion of the film cover skirt material 64 is bonded to the innersurface of the case 20. Accordingly, the light exposure opening portion26 and the claw opening portion 32 are blocked by the film cover 60.Then, the instant film 10 is accommodated in the case main body 22 in astate where the instant film 10 is stacked. The instant film 10 isstacked with the light exposure surface 10 a (refer to FIG. 4) as thetop of the instant film 10. The instant film 10 is accommodated in thecase main body 22 such that the light exposure surface 10 a is directedtoward the light exposure opening portion 26 side. Accordingly, the filmcover 60 and the instant film 10 are accommodated in the case main body22 in a state where the film cover 60 is placed on the light exposuresurface 10 a of the instant film 10 positioned in the uppermost part.Then, the rear surface of the case main body 22 is closed with the caselid 24. Accordingly, the assembly of the instant film pack 1 iscompleted.

<Manner of Using Instant Film Pack>

The instant film pack 1 can be used in both manners of using the instantfilm pack 1 by detaching the film cover 60 and using the instant filmpack 1 without detaching the film cover 60. In the printer 300 of thepresent embodiment, the instant film pack 1 is loaded into the printer300 and then, is used by detaching (discharging) the film cover 60. Inthis case, the instant film 10 is exposed to light by the light exposurehead 25 (refer to FIG. 6 and FIG. 7) after being transported from thecase 20, and printing is performed by spreading the developer using thespread rollers 40 (refer to FIG. 6 and FIG. 7). The transport and lightexposure (printing) are sequentially performed from the instant film 10positioned in the uppermost part in the case to the instant film 10positioned in a lower part. The transport, discharge, and light exposurefor the film cover 60 and the instant film 10 will be described below.

<Main Configuration of Printer>

Next, arrangement of main constituents related to the transport,discharge, and light exposure for the film cover 60 and the instant film10 in the printer 300 will be described. FIG. 6 is a perspective viewillustrating the arrangement of components related to the transport,discharge, and light exposure, and FIG. 7 is a top view in a stateillustrated in FIG. 6. In FIG. 6 and FIG. 7, illustrations of componentsthat are not description targets are appropriately omitted, and theshapes, dimensions, and arrangement of components are illustrated in anappropriately simplified manner. In addition, a schematic configurationof a control system of the printer 300 is illustrated in FIG. 9.

As illustrated in FIG. 6 and FIG. 7, on a downstream side in thetransport direction F of the instant film pack 1, a film detectionsensor 27, the light exposure head 25 (line head), a capstan roller 35(transport unit), a pinch roller 39 (transport unit), and the pair ofspread rollers 40 (a roller 40 a and a roller 40 b) (transport unit) arearranged in this order from an upstream side to the downstream side. Theposition of each unit is fixed.

<Film Detection Sensor>

The film detection sensor 27 is a sensor for detecting the position ofthe instant film 10. A photointerrupter type or reflection detectiontype sensor can be used. In a case where the film detection sensor 27detects the film cover 60 or the instant film 10, a system controller 45(control unit) starts counting a pulse signal that is detected by anencoder signal processing device 52. The position of the film cover 60or the instant film 10 can be found using the number of counts of thepulse signal. The position of the film cover 60 or the instant film 10detected in such a manner is used in control of a light exposure starttiming and a transport speed control in a case of passing the instantfilm 10 to the capstan roller 35 from the claw member 72.

<Light Exposure Head and Light Exposure Head Driving Unit>

The light exposure head 25 is a line type light exposure head and isarranged in a direction in which a longitudinal direction is orthogonalto the transport direction F of the film cover 60 and the instant film10. An LED array (not illustrated) in which minute light emitting diodes(LED) that emit red, green, and blue in units of pixels are lined up inthe longitudinal direction is disposed inside the light exposure head25. Light from the LED array of each color is transmitted through amicrolens array (not illustrated) that is disposed on a front surface ofthe LED array, and the same line of the instant film 10 is irradiatedwith the light. Accordingly, light exposure is performed on the instantfilm 10 for each line using three colors at the same time, and lightexposure corresponding to a line image corresponding to one line isperformed by one instance of light exposure performed by the lightexposure head 25.

The light exposure head driving unit 73 (refer to FIG. 9; control unit)drives the light exposure head 25 based on the image data received fromthe smartphone 200. At this point, the light exposure head driving unit73 controls the light exposure timing and the like of the light exposurehead 25 for the line image based on an encoder signal (pulse signal)that is output by the rotary encoder 36 as will be described below.

In the printer 300, by the light exposure head 25 and the light exposurehead driving unit 73 having the above configuration, the light exposuresurface 10 a of the instant film 10 transported by the capstan roller 35and the pinch roller 39 is irradiated with printing light one line at atime, and the image is printed on the instant film 10. In a case wherethe printer 300 receives the data of the template from the smartphone200, the received template is printed on the instant film 10 along withthe image.

<Capstan Roller>

The capstan roller 35 is connected to a direct-current (DC) motor 30through a deceleration gear array (not illustrated) disposed in acapstan roller driving unit 34 (refer to FIG. 9) and is embedded on thelight exposure surface 10 a side of the instant film 10. As illustratedin FIG. 7, the capstan roller 35 is arranged in the vicinity of a lightemitting unit of the light exposure head 25. A pair of disc shapedrollers 35 a and 35 b for holding end portions of the film cover 60 andthe instant film 10 are arranged in an end portion of the capstan roller35. The rollers 35 a and 35 b securely hold the end portion of theinstant film 10 using multiple minute protrusions 35 c on the surface ofthe rollers.

<Rotary Encoder>

In addition, as illustrated in FIG. 6 to FIG. 8, a rotating slit plate(circular plate) 37 that constitutes the optical rotary encoder(encoder) 36 is arranged on the same axis as a rotating shaft of thecapstan roller 35. A detection unit 38 that includes a light emittingelement consisting of a light emitting diode or the like and a lightreceiving element such as a photodiode with the rotating slit plate 37interposed therebetween is fixed.

In the present example, 200 slits 37 a (FIG. 6) are formed around therotating slit plate 37. Each slit 37 a has a slit width of 100 μm, and apitch between slits is 200 μm.

In a case where the rotating slit plate 37 rotates along with rotationof the rotating shaft of the capstan roller 35, each time the slits 37 aformed in the rotating slit plate 37 pass between the light emittingelement and the light receiving element, light of irradiation from thelight emitting element through the rotating slit plate 37 is transmittedthrough the slits 37 a and is incident on the light receiving element,and an electric signal that corresponds to the amount of incident lightis output from the light receiving element. Accordingly, an electricsignal (an electric signal having a triangular wave shape) that has thesame cycle as the cycle of the slits 37 a passing through the detectionunit 38 is output from the detection unit 38 of the rotary encoder 36.

The rotary encoder 36 in the present example includes a comparator thatamplifies the triangular wave shaped electric signal output from thedetection unit 38 and shapes the waveform of the electric signal into arectangular wave (pulse signal), and an encoder signal that includes apulse signal having a cycle corresponding to the rotational speed (thetransport speed of the instant film 10) of the rotating slit plate 37(capstan roller 35) is output.

The encoder signal processing device 52 inputs the encoder signal fromthe rotary encoder 36, detects the pulse signal (a rise and/or a fall ofthe pulse signal) included in the encoder signal, and outputs thedetected pulse signal to the system controller (control unit) 45. Theencoder signal processing device 52 has a function of removing a noisesignal included in the encoder signal and generating a lost pulsesignal. Details of such a function will be described below.

The system controller 45 controls a printing timing (light exposuretiming) of the light exposure head 25 for the line image as will bedescribed below in synchronization with the pulse signal input from theencoder signal processing device 52.

<Pinch Roller>

The pinch roller 39 is formed of an elastic material such as rigidurethane and is arranged to face the capstan roller 35. In addition, thepinch roller 39 is rotationally driven by the capstan roller 35. Coilsprings, not illustrated, are connected to both end portions of thepinch roller 39. By biasing of the coil springs, the pinch roller 39typically abuts the capstan roller 35. By rotating the pinch roller 39and the capstan roller 35 with the instant film 10 sandwichedtherebetween (refer to FIG. 8), the instant film 10 can be transportedto the spread rollers 40.

<Spread Roller>

As illustrated in FIG. 6, the spread rollers 40 are arranged to faceeach other with two spread rollers 40 as one set. The spread rollers 40is formed of, for example, a metal member and is formed to have the samediameter as the diameter of the capstan roller 35. One roller 40 a ofthe one set of spread rollers 40 is arranged on the same side as thecapstan roller 35 and is connected to the DC motor 30 through adeceleration gear and a torque limiter, not illustrated, of a spreadroller driving unit 41 (refer to FIG. 9). By embedding the torquelimiter, a torque generated in the spread rollers 40 can be regulated ina case where the torque generated in the spread rollers 40 becomesgreater than or equal to a set torque. In addition, in the same manneras the pinch roller 39, coil springs (not illustrated) are connected toboth ends of the roller 40 b facing the roller 40 a. By a biasing forceof the coil springs, the roller 40 b is rotationally driven by theroller 40 a on the fixed side with the instant film 10 interposedtherebetween. The spread rollers 40 break the pod portion 14 disposed inthe instant film 10 by sandwiching the pod portion 14 (refer to FIG. 8)and spread the developing treatment liquid on a photosensitive layerinside the instant film 10.

<Transport of Film Cover and Instant Film>

In a case where the instant film pack 1 that is not used is loaded intothe printer 300, the system controller 45 controls driving of the DCmotor 30 (transport unit) through a motor driver 46 in order toautomatically transport (discharge) the film cover 60 by detecting theloading of the non-used instant film pack 1. In addition, in a casewhere the image data and the printing instruction are received from thesmartphone 200, the system controller 45 controls driving of the DCmotor 30 through the motor driver 46 in order to perform light exposure,developing, and spreading while transporting the instant film 10 that isnot subjected to light exposure.

The motor driver 46 is supplied with a direct current power supply froma battery or an alternating current (AC) adapter, not illustrated. Themotor driver 46 supplies driving electric power of a predeterminedvoltage to the DC motor 30 based on a driving instruction that is inputfrom the system controller 45. In the present example, an inexpensivetransport device is implemented such that during the transport of thefilm cover 60 and the instant film 10, a constant voltage is applied tothe DC motor 30 from the motor driver 46, and a speed control or thelike such as speed feedback is not performed.

In addition, the system controller 45 transmits signals to a lightexposure control unit 47 and a line memory 48. The claw driving unit 71is operated by driving the DC motor 30. The claw member 72 enters fromthe claw opening portion 32 formed in the instant film pack 1 and islocked at the proximal end of the film cover 60 or the instant film 10in the uppermost layer (refer to FIG. 10). The distal end of the filmcover 60 or the instant film 10 is forwarded in the transport directionF from the discharge port 28. In addition, by driving of the DC motor30, the capstan roller 35 starts rotating, and the pinch roller 39 isrotationally driven by the rotation of the capstan roller 35.

The film cover 60 or the instant film 10 moves in the transportdirection F along with the movement of the claw member 72. In a casewhere the film cover 60 or the instant film 10 reaches the position ofthe film detection sensor 27, the film detection sensor 27 detects thefilm cover 60 or the instant film 10. Accordingly, the system controller45 starts counting the pulse signal input from the encoder signalprocessing device 52. Light exposure and transport are controlled basedon the number of counts of the pulse signal.

The claw member 72 continues moving from the state illustrated in FIG.10 and forwards the film cover 60 or the instant film 10 between thecapstan roller 35 and the pinch roller 39 (refer to FIG. 11).Accordingly, the film cover 60 or the instant film 10 starts enteringbetween the capstan roller 35 and the pinch roller 39, and passing fromthe claw member 72 to the capstan roller 35 and the pinch roller 39 isstarted. While the passing is performed, the film cover 60 or theinstant film 10 is transported by the capstan roller 35 and the pinchroller 39 in addition to the claw member 72.

In a state where the claw member 72 reaches an end of a movement rangeby continuing the transport (refer to FIG. 12), the film cover 60 or theinstant film 10 is in a state where the film cover 60 or the instantfilm 10 completely enters between the capstan roller 35 and the pinchroller 39. Accordingly, the passing of the film cover 60 or the instantfilm 10 is finished, and the claw member 72 starts receding in adirection opposite to the transport direction F. After the passing, thetransport is continuously performed by the capstan roller 35 and thepinch roller 39.

In the above transport, the movement range (a distance between aposition illustrated in FIG. 10 and a position illustrated in FIG. 12)and the movement speed of the claw member 72 can be set using a gear, acam member, a link member, or the like (not illustrated) in the clawdriving unit 71 in addition to the rotational speed of the DC motor 30.Similarly, the rotational speed of the capstan roller 35 can be setusing a gear or the like (not illustrated) in the capstan roller drivingunit 34 in addition to the rotational speed of the DC motor 30.

[Encoder Signal Processing Device]

Next, the encoder signal processing device disposed in the printer willbe described in detail.

FIG. 13 is a block diagram illustrating a first embodiment of theencoder signal processing device 52 (FIG. 9) disposed in the printer300.

As illustrated in FIG. 13, the encoder signal processing device 52 ismainly configured with an encoder signal input unit 521, a pulse signaldetection unit 522, an effective detection period setting unit 523, apulse signal generation unit 524, and a pulse signal combining unit 525.The encoder signal processing device 52 may be configured with a digitalcircuit or may be configured with one or a plurality of centralprocessing units (CPU) in the printer 300, software for processing theencoder signal, and the like.

The rotary encoder 36 outputs the encoder signal that includes the pulsesignal having a cycle corresponding to the rotational speed (thetransport speed of the instant film 10) of the rotating slit plate 37(capstan roller 35). As described above, 200 slits 37 a (FIG. 6) areformed around the rotating slit plate 37 in the present example. Thus,the rotary encoder 36 generates one pulse signal each time the capstanroller 35 rotates by 1.8 degrees. In addition, the slit width of eachslit 37 a formed in the rotating slit plate 37 in the present example is100 μm. Thus, in a case where dust having a size of greater than orequal to 100 μm is attached to the slit 37 a, the pulse signalcorresponding to the slit 37 a to which the dust is attached is lost.

In FIG. 13, the encoder signal is input into the encoder signal inputunit 521 from the rotary encoder 36.

FIG. 14 illustrates one example of the waveform of the encoder signal.The encoder signal illustrated in the drawing includes a rectangularpulse signal A that is generated in correspondence with the slits 37 aof the rotating slit plate 37, and a noise signal B that is mixed withthe encoder signal. In addition, a part C of the encoder signal that isillustrated using a dot-dashed line indicates a position at which thepulse signal that is lost by the dust attached to the slit 37 a of therotating slit plate 37 occurs.

The pulse signal detection unit 522 is a part that detects the pulsesignal A from the encoder signal input into the encoder signal inputunit 521, and detects the pulse signal A (in the present example, atiming of moment of a rise of the signal included in the encoder signal)only within an effective detection period that is set by the effectivedetection period setting unit 523.

The effective detection period setting unit 523 sets the effectivedetection period for detecting the subsequent pulse signal, each timethe pulse signal is detected by the pulse signal detection unit 522.

In FIG. 14, in a case where the pulse signal detection unit 522 detectsthe pulse signal from the encoder signal at time t₀, the effectivedetection period setting unit 523 sets the effective detection periodbased on time t₀ at which the pulse signal is detected, a cycle T₁ thatis acquired from a plurality of most recent detected pulse signals, andthe width of change in the transport speed of the instant film 10.

FIG. 15 is a graph illustrating one example of the transport speed ofthe instant film 10. In FIG. 15, V₀, ΔV, and x₀ to x₄ are as follows.

V₀: a reference transport speed of the instant film 10

ΔV: the width of change (maximum width of change) in the transport speedof the instant film 10

x₀: the position of instant film 10 at a timing of moment of the distalend of the instant film 10 entering between the capstan roller 35 andthe pinch roller 39

x₁: the distal end position of the instant film 10 at which lightexposure on the instant film 10 is started

x₂: a position at which the pod portion 14 of the instant film 10reaches the pair of spread rollers 40

x₃: a position at which the pod portion 14 of the instant film 10 passesthrough the pair of spread rollers 40

x₄: the distal end position of the instant film 10 at which lightexposure on the instant film 10 is finished

As illustrated in FIG. 15, by the constant voltage supplied to the DCmotor 30, the instant film 10 is typically transported at the referencetransport speed V₀ that corresponds to the constant voltage. However,load is exerted when the distal end of the instant film 10 entersbetween the capstan roller 35 and the pinch roller 39, and when the podportion 14 of the instant film 10 is squeezed by the pair of spreadrollers 40. A transport speed V of the instant film 10 becomes lowerthan the reference transport speed V₀ depending on the load and becomesslightly higher than the reference transport speed V₀ when the load isreduced (overshoot).

The cycle of the pulse signal A included in the encoder signal outputfrom the rotary encoder 36 may change depending on the rotational speed(that is, the transport speed V of the instant film 10 transported bythe capstan roller 35) of the rotating slit plate 37 (capstan roller 35)of the rotary encoder 36. However, the transport speed V of the instantfilm 10 does not rapidly change, and the maximum width of change ΔV inthe transport speed V of the instant film 10 is known.

Accordingly, as illustrated in FIG. 14, in a case where the pulse signaldetection unit 522 detects the pulse signal from the encoder signal attime t₀, the effective detection period setting unit 523 sets a period(effective detection period) Δt between time t₁ and time t₃, whereintime t₁ is a time before time t₂ and time t₃ is a time after time t₂,and time t₂ is a time after the cycle T₁ from time t₀ at which the pulsesignal is detected. In addition, the width of time period of theeffective detection period Δt is preferably determined based on themaximum width of change ΔV in the transport speed V of the instant film10 and is more preferably the minimum width of time period such that atiming of moment of a rise of the pulse signal A can be detected even ina case where a change in the transport speed V of the instant film 10 isequal to the maximum thereof.

In addition, the effective detection period setting unit 523 acquiresthe cycle T₁ corresponding to the current transport speed V of theinstant film 10 from the plurality of most recent pulse signals detectedby the pulse signal detection unit 522.

FIG. 16 is a partial enlarged view of a graph illustrating the transportspeed of the instant film 10 illustrated in FIG. 15. In FIG. 16, a blackcircle on the graph indicates a timing of moment of detecting the pulsesignal from the encoder signal.

In FIG. 16, in a case where a timing of moment of detecting the pulsesignal corresponding to any light exposure timing for the instant film10 is denoted by t_(i), a cycle T of the pulse signal that is used fordetecting the subsequent pulse signal is calculated based on adifference in time between each timing (t_(i-3), t_(i-2), t_(i-1), andt_(i)) of moment of detecting a plurality of pulse signals before thelight exposure timing (including the pulse signal corresponding to thelight exposure timing).

In the example illustrated in FIG. 16, three cycles can be calculatedfrom the timing (t_(i-3), t_(i-2), t_(i-1), and t_(i)) of moment ofdetecting four pulse signals. Thus, the average of three cycles is usedas the cycle T of the pulse signal used for detecting the subsequentpulse signal.

The number of plurality of pulse signals before the light exposuretiming is not limited the embodiment. One cycle may be obtained from twopulse signals, or the cycle of the average of two or more cyclesacquired from three or more pulse signals may be obtained.

Returning to FIG. 13, as described above, the pulse signal detectionunit 522 detects the pulse signal only within the effective detectionperiod set by the effective detection period setting unit 523 from theinput encoder signal and detects the subsequent pulse signal only withinthe effective detection period Δt from time t₁ to time t₃ in a casewhere the pulse signal (a rise of the encoder signal) is detected attime t₀ as illustrated in FIG. 14.

Accordingly, even in a case where the noise signal B is mixed in aperiod other than the effective detection period Δt, the noise signal isnot erroneously detected as the pulse signal, and the noise signal B canbe substantially removed.

In addition, the pulse signal detection unit 522 detects only theinitial pulse signal (the initial rise of the encoder signal) within theeffective detection period set by the effective detection period settingunit 523. Accordingly, even in a case where the noise signal is mixedwithin the effective detection period, one pulse signal can be detected.Even in a case where the initial detected pulse signal within theeffective detection period is the pulse signal caused by the noisesignal, the pulse signal is the pulse signal detected within theeffective detection period. Thus, the pulse signal does not cause anyproblem in a case where the pulse signal is used in a process in asubsequent stage.

As illustrated in FIG. 14, in a case where the pulse signal detectionunit 522 detects the pulse signal at time t₂, the effective detectionperiod setting unit 523 sets the effective detection period fordetecting the subsequent pulse signal using time t₂ as a reference.

In the example illustrated in FIG. 14, the effective detection period Δtfrom time t₄ to time t₆ is set using a cycle T₂ of the most recent pulsesignal and the width of time period of the effective detection periodΔt. In the effective detection period Δt, a rise of the encoder signalis not present (a rectangular pulse signal that is to be originallygenerated in the part C illustrated using a dot-dashed line is lost),and the pulse signal detection unit 522 can detect the pulse signalwithin the effective detection period Δt from time t₄ to time t₆.

The pulse signal generation unit 524 illustrated in FIG. 13 is suppliedwith the pulse signal (the pulse signal that is in synchronization witha rise of the encoder signal) detected by the pulse signal detectionunit 522 and information indicating the effective detection period setby the effective detection period setting unit 523. In a case where thepulse signal is not input from the pulse signal detection unit 522within the effective detection period, the pulse signal generation unit524 generates the pulse signal after the effective detection period andoutputs the generated pulse signal. In the example illustrated in FIG.14, the pulse signal generation unit 524 outputs the generated pulsesignal immediately after (time t₆) the effective detection period Δtfrom time t₄ to time t₆.

In addition, as described above, in a case where the pulse signalgeneration unit 522 does not detect the pulse signal within theeffective detection period Δt from time t₄ to time t₆, the effectivedetection period setting unit 523 sets the effective detection periodfor detecting the subsequent pulse signal using time t₂ at which thepulse signal is detected by the pulse signal detection unit 522 as areference. In this case, the effective detection period Δt from time t₇to time t₉ is set using the width of time period of the effectivedetection period Δt and a cycle (2T₂) that is double the cycle T₂.

The pulse signal combining unit 525 combines the pulse signal detectedby the pulse signal detection unit 522 and the pulse signal generated bythe pulse signal generation unit 524 and outputs the combined pulsesignal to the system controller 45.

Accordingly, the encoder signal processing device 52 can remove theeffect of the noise signal and can output a favorable pulse signal (thepulse signal having a cycle corresponding to the transport speed of theinstant film 10) even in a case where the original pulse signal is lostfrom the encoder signal by dust attached to the slit 37 a of therotating slit plate 37.

FIG. 17 is a block diagram illustrating a second embodiment of anencoder signal processing device that can be applied to the printer 300.Common parts in the encoder signal processing device 52 of the firstembodiment illustrated in FIG. 13 will be designated by the samereference signs, and detailed description of such parts will not berepeated.

An encoder signal processing device 52-2 of the second embodimentillustrated in FIG. 17 is different from the encoder signal processingdevice 52 of the first embodiment in that a delay circuit 526 is addedbetween the pulse signal detection unit 522 and the pulse signalcombining unit 525.

The delay circuit 526 inputs the pulse signal detected by the pulsesignal detection unit 522 and outputs the input pulse signal by delayingthe input pulse signal by a certain time period. The certain time periodof delay made by the delay circuit 526 is preferably a time period thatcorresponds to the effective detection period set by the effectivedetection period setting unit 523.

As illustrated in FIG. 14, in a case where the pulse signal detectionunit 522 does not detect the pulse signal within the effective detectionperiod, the pulse signal generation unit 524 generates (outputs) thepulse signal immediately after (time t₆) the effective detection period.

In a case where the pulse signal is not lost from the encoder signal,and the transport speed of the instant film 10 does not change, thepulse signal is detected at time t₅ after the cycle T₂ from time t₂ atwhich the previous pulse signal is detected.

Accordingly, compared to the pulse signal that is to be originallydetected by the pulse signal detection unit 522, the pulse signalgenerated (output) by the pulse signal generation unit 524 is output ina delayed manner and, in the example illustrated in FIG. 14, is delayedby a difference of time t₆−time t₅ and output.

The delay circuit 526 delays the pulse signal output from the pulsesignal detection unit 522 by the delay of the pulse signal output fromthe pulse signal generation unit 524.

Accordingly, in a case where the pulse signal is output from the pulsesignal generation unit 524, the cycle of each pulse signal combined bythe pulse signal combining unit 525 can be made uniform (the cycle morecorrectly reflects the transport speed of the instant film 10).

[Light Exposure Control]

As illustrated in FIG. 9, the system controller 45 drives the lightexposure head driving unit 73 in synchronization with the pulse signalinput from the encoder signal processing device 52, thereby controllingthe light exposure timing of the light exposure head 25, and controlsthe amount of light emission of each color of red, green, and blueemitted from the light exposure head 25 through the light exposurecontrol unit 47 (control unit), the line memory 48, and the lightexposure head driving unit 73.

The system controller 45 sequentially supplies image data of red, green,and blue corresponding to one line in the image data received throughthe wireless communication unit 75 to the line memory 48 and temporarilyretains the image data of red, green, and blue corresponding to one linein the line memory 48.

In addition, the system controller 45 obtains the current transportspeed of the instant film 10 based on the pulse signal input from theencoder signal processing device 52 and outputs a transport speed signalindicating the obtained transport speed to the light exposure controlunit 47.

As described using FIG. 16, the transport speed of the instant film 10can be obtained using the cycle (the cycle of the average in a casewhere two or more cycles are acquired) acquired from the plurality ofpulse signals before the light exposure timing.

The light exposure control unit 47 includes a density correction unit 47a and outputs a pulse width modulation (PWM) signal to the lightexposure head 25 or outputs the PWM signal of which the pulse width iscorrected by the density correction unit 47 a, such that the amount oflight emission emitted from each LED of the light exposure head 25 isset to an amount of light emission corresponding to each pixel value(for example, 0 to 255) of the image data.

That is, the light exposure control unit 47 generates the PWM signal byperforming pulse width modulation of each pixel value of the image databased on the image data of red, green, and blue corresponding to oneline temporarily retained in the line memory 48.

The density correction unit 47 a is a part that corrects the density ofthe image to be printed on the instant film to the same density as in acase where the instant film 10 is transported at the reference transportspeed (the reference transport speed V₀ illustrated in FIG. 15),regardless of the transport speed of the instant film 10. The densitycorrection unit 47 a corrects the pulse width of the generated PWMsignal based on the transport speed signal that indicates the currenttransport speed of the instant film 10 and is input from the systemcontroller 45.

The correction of the pulse width of the PWM signal performed by thedensity correction unit 47 a is such that the light emission time periodof the light exposure head 25 is decreased in a case where the transportspeed of the instant film 10 is lower than the reference transport speedV₀, and the light emission time period of the light exposure head 25 isincreased in a case where the transport speed of the instant film 10 ishigher than the reference transport speed V₀.

The PWM signal corrected by the density correction unit 47 a is outputto the light exposure head driving unit 73.

A light exposure timing signal that is in synchronization with the pulsesignal of the encoder signal is supplied as another input into the lightexposure head driving unit 73 from the system controller 45. The lightexposure head driving unit 73 amplifies the PWM signal input from thelight exposure control unit 47 and outputs the amplified PWM signal tothe light exposure head 25 in synchronization with the light exposuretiming signal input from the system controller 45.

The light exposure head 25 causes each LED of the light exposure head 25to emit light based on the PWM signal supplied from the light exposurehead driving unit 73 and performs simultaneous three color lightexposure on the light exposure surface 10 a of the instant film 10.

FIG. 18 is a view illustrating correction (density correction) of thelight exposure timing and the amount of light emission of the lightexposure head 25 that performs light exposure in synchronization withthe pulse signal of the encoder signal. The example illustrated in FIG.18 illustrates the PWM signal that controls light emission of one red(R) LED of the light exposure head 25.

As illustrated in the drawing, the light exposure timing of the lightexposure head 25 is controlled in synchronization with the pulse signal(a rise of the pulse signal) of the encoder signal.

In addition, in the example illustrated in FIG. 18, the transport speedV of the instant film 10 becomes lower than the reference transportspeed V₀. Consequently, correction is performed such that the pulsewidth is decreased by ΔW from the pulse width of the PWM signal in acase where the instant film 10 is transported at the reference transportspeed V₀. That is, correction is performed such that the light emissiontime period is decreased by ΔW, and the amount of light emission isdecreased.

The amount of correction ΔW of the pulse width corresponds to the amountof change in the speed of the instant film 10 with respect to thereference transport speed V₀.

The light exposure timing of light exposure on the instant film 10performed by the light exposure head 25 for the line image is insynchronization with the pulse signal of the encoder signal. Thus, thenumber of line images per unit forwarding amount of the instant film 10is constant regardless of the transport speed V of the instant film 10and is not affected by the transport speed V of the instant film 10.Accordingly, the transport speed of the instant film 10 does not need tobe accurately controlled to a constant speed, and a transport device forthe instant film can be implemented using an inexpensive device.

In a case where the transport speed V of the instant film 10 changes,and the transport speed V becomes lower or higher than the referencetransport speed V₀, unevenness having a shape of streaks occurs in apart where the transport speed V changes. However, as described above,since the correction (density correction) of the amount of lightemission corresponding to the transport speed of the instant film 10 isperformed through the density correction unit 47 a, unevenness having ashape of streaks can be prevented from occurring in the image printed onthe instant film 10.

In the present example, the instant film 10 is an instant film having apositive photosensitizer. For an instant film having a negativephotosensitizer, the correction of the amount of light emission isperformed in an opposite manner to that for the instant film having apositive photosensitizer. For example, the amount of light emission ofthe light exposure head 25 is increased as the transport speed of theinstant film having a negative photosensitizer is decreased.

In addition, while the amount of light emission of the light exposurehead 25 is controlled using the PWM signal (light emission time period)in the present example, the present invention is not limited. The amountof light emission of the light exposure head 25 may be implemented bycontrolling the light emission intensity of the light exposure head orcontrolling both the light emission time period and the light emissionintensity.

[Printer-Equipped Imaging Apparatus]

FIG. 19 is a perspective exterior view of a printer-equipped camera 500(printer-equipped imaging apparatus) according to a second embodimentseen from a front surface side. In the same manner as the printer 300(refer to FIG. 2), a loading chamber 515 is disposed in theprinter-equipped camera 500, and a film pack is loaded. The loadingchamber 515 is closed with an openable and closable lid member 509. Theinstant film pack 1 that is the same as that of the printer 300 is usedas the film pack. In a case where the lid member 509 is closed after theinstant film pack 1 is loaded, an uplifting member 520 that is disposedin the lid member 509 is inserted into the uplifting member insertionparts 33 and uplifts the light shielding sheet 50 (refer to FIG. 3) tothe front surface side (the opposite side of the uplifting memberinsertion parts 33 from the opening surface), and the instant film 10 ispressed to the inner surface of the case 20. In the followingdescription, the same configurations as those in the printer 300 will bedesignated by the same reference signs, and detailed descriptions ofsuch configurations will not be repeated.

<Camera Main Body>

As illustrated in FIG. 19, an objective finder window 504, a capturinglens 505 equipped with a zoom function, a release button 506, a strobelight emitting unit, and a photometric light reception window areexposed on the front surface of the camera main body 503. In addition,the lid member 509 is disposed in a central portion of the camera mainbody 503. A film discharge port 510 (dotted line in the drawing) isdisposed on the upper surface of the camera main body 503 and istypically covered with a discharge port lid 511.

<Configuration of Printer-Equipped Camera>

FIG. 20 is a block diagram illustrating a configuration of theprinter-equipped camera 500. An imaging element 575 is arranged behindthe capturing lens 505. A subject image is formed on a light receptionsurface of the imaging element 575 by the capturing lens 505. Theimaging element 575 is driven by an imaging element driver 576. Theimaging element 575 converts the optical subject image into an electricimaging signal and outputs the electric imaging signal. A charge coupleddevice (CCD) type or a complementary metal-oxide semiconductor (CMOS)type imaging element can be used as the imaging element 575.

Color filters of red, green, and blue are arranged in a matrix form on aphotoelectric surface of the imaging element 575. An imaging signal thatis output for each color is amplified by an amplifier 577 and then, issubjected to digital conversion by an analog to digital (A/D) converter578. The A/D converter 578 generates image data by performing digitalconversion of the imaging signal and inputs the image data into an imagedata processing circuit 579. The capturing lens 505, the imaging element575, the imaging element driver 576, the A/D converter 578, and theimage data processing circuit 579 that function as an imaging unitconstitute an image data input unit.

The image data processing circuit 579 performs signal processing such aswhite balance adjustment and gamma correction on the input image dataand outputs the image data to a video signal output terminal 582 througha digital to analog (D/A) converter 580 and an amplifier 581, andoutputs the image data to an LCD driver 554 and displays a video on anLCD panel 532. In addition, the image data output by the image dataprocessing circuit 579 is printed on the instant film 10 using the lightexposure head 25 and the like under control of the system controller 45.

[Printing Method]

FIG. 21 is a flowchart illustrating a printing method including anencoder signal processing method.

In FIG. 21, the encoder signal processing device 52 of the printer 300inputs the encoder signal from the rotary encoder 36 (step S10).

In a case where the pulse signal detection unit 522 detects the pulsesignal from the encoder signal, the effective detection period settingunit 523 (FIG. 13) of the encoder signal processing device 52 sets theeffective detection period for detecting the subsequent pulse signal(step S12). The pulse signal detection unit 522 detects the pulse signalfrom the encoder signal within the set effective detection period (stepS14 and FIG. 14).

The pulse signal generation unit 524 of the encoder signal processingdevice 52 determines whether or not the pulse signal detection unit 522detects the pulse signal within the effective detection period (stepS16), and generates (outputs) the pulse signal after the effectivedetection period (step S18 and FIG. 14) in a case where the pulse signalis not detected (in the case of “No”).

The pulse signal combining unit 525 of the encoder signal processingdevice 52 outputs the pulse signal detected by the pulse signaldetection unit 522 and the pulse signal generated by the pulse signalgeneration unit 524 (step S20).

The light exposure control unit 47 generates the PWM signal (the PWMsignal corresponding to each pixel value of the image data) for drivingthe light exposure head 25 based on the image data corresponding to oneline. The density correction unit 47 a in the light exposure controlunit 47 corrects the pulse width of the PWM signal based on thetransport speed signal indicating the transport speed of the instantfilm (step S22). The correction of the pulse width of the PWM signal issuch that the light emission time period of the light exposure head 25is decreased in a case where the transport speed of the instant film islower than the reference transport speed, and the light emission timeperiod of the light exposure head 25 is increased in a case where thetransport speed of the instant film is higher than the referencetransport speed.

The light exposure head driving unit 73 amplifies the PWM signal inputfrom the light exposure control unit 47 and outputs the amplified PWMsignal to the light exposure head 25 in synchronization with the pulsesignal (the light exposure timing signal corresponding to the pulsesignal) of the encoder signal. Accordingly, the light exposure timing ofthe light exposure head 25 is controlled in synchronization with thepulse signal, and light exposure is performed for the line imagecorresponding to one line (step S24).

Next, the system controller 45 determines whether or not printing on oneinstant film is finished (step S26). In a case where printing is notfinished (in the case of “No”), a return is made to step S10, and theprocesses from step S10 to step S26 are repeated. In a case whereprinting is finished (in the case of “Yes”), the present process isfinished.

[Others]

While the encoder signal processing device of the present embodimentprocesses the encoder signal output from the rotary encoder disposed inthe printer, the present invention is not limited. An encoder signalincluding a pulse signal having a cycle corresponding to a transportspeed of a transported body from an encoder detecting the transportspeed of the transported body other than the printing medium may beprocessed.

In addition, the encoder signal is not limited to the encoder signaloutput from the rotary encoder and may be an encoder signal that isoutput from another kind of encoder such as a linear encoder.

Furthermore, the printing medium is not limited to the instant film thatsenses light depending on the amount of light and may be, for example,thermal paper on which printing is performed using heat. In this case, athermal head is applied as the line head instead of the light exposurehead.

In addition, the present invention is not limited to each embodimentdescribed above. It is apparent that the configurations of eachembodiment can be appropriately combined, or various modifications canbe made without departing from the spirit of the present invention.

EXPLANATION OF REFERENCES

-   -   1: instant film pack    -   10: instant film    -   10 a: light exposure surface    -   10 b: observation surface    -   12: light exposure portion    -   14: pod portion    -   14 a: developing treatment liquid pod    -   16: trap portion    -   16 a: absorbing material    -   18: observation portion    -   20: case    -   22: case main body    -   22 a: front surface part    -   22 c: bottom surface portion    -   24: case lid    -   25: light exposure head    -   26: light exposure opening portion    -   27: film detection sensor    -   28: discharge port    -   29: case flap material    -   30: DC motor    -   31: film support unit    -   32: claw opening portion    -   32 a: entrance portion    -   32 b: passage portion    -   33: uplifting member insertion part    -   34: capstan roller driving unit    -   35: capstan roller    -   35 a, 35 b, 40 a, 40 b: roller    -   35 c: minute protrusion    -   36: rotary encoder    -   37: rotating slit plate    -   37 a: slit    -   38: detection unit    -   39: pinch roller    -   40: spread roller    -   41: spread roller driving unit    -   42: light shielding sheet attaching unit    -   45: system controller    -   46: motor driver    -   47: light exposure control unit    -   47 a: density correction unit    -   48: line memory    -   50: light shielding sheet    -   52, 52-2: encoder signal processing device    -   53: first light shielding sheet    -   53 b: fixed portion    -   54: second light shielding sheet    -   60: film cover    -   62: notch portion    -   64: film cover skirt material    -   71: claw driving unit    -   72: claw member    -   73: light exposure head driving unit    -   75: wireless communication unit    -   100: printing system    -   200: smartphone    -   300: printer    -   311: film discharge port    -   302: lid member    -   304: uplifting member    -   315: loading chamber    -   500: printer-equipped camera    -   503: camera main body    -   504: objective finder window    -   505: capturing lens    -   506: release button    -   509: lid member    -   510: film discharge port    -   511: lid    -   515: loading chamber    -   521: encoder signal input unit    -   522: pulse signal detection unit    -   523: effective detection period setting unit    -   524: pulse signal generation unit    -   525: pulse signal combining unit    -   526: delay circuit    -   532: LCD panel    -   554: LCD driver    -   575: imaging element    -   576: imaging element driver    -   577: amplifier    -   578: A/D converter    -   579: image data processing circuit    -   580: D/A converter    -   581: amplifier    -   582: output terminal    -   S10 to S26: step    -   T, T₁, T₂: cycle    -   ΔV: width of change    -   ΔW: amount of correction    -   Δt: effective detection period

What is claimed is:
 1. An encoder signal processing device comprising:an encoder signal input unit that inputs an encoder signal including apulse signal having a cycle corresponding to a transport speed of atransported body from an encoder detecting the transport speed of thetransported body; an effective detection period setting unit that setsan effective detection period for detecting a subsequent pulse signaleach time the pulse signal is detected from the input encoder signal; apulse signal detection unit that detects the pulse signal from theencoder signal only within the set effective detection period; and apulse signal generation unit that generates the pulse signal after theeffective detection period in a case where the pulse signal is notdetected from the encoder signal within the effective detection period.2. The encoder signal processing device according to claim 1, whereinthe effective detection period setting unit sets the effective detectionperiod based on a cycle of a plurality of the most recent pulse signalsdetected by the pulse signal detection unit and a width of change in thetransport speed of the transported body.
 3. The encoder signalprocessing device according to claim 2, wherein the plurality of mostrecent pulse signals are three or more pulse signals, and the cycle ofthe pulse signal is a cycle of an average of two or more cycles acquiredfrom the three or more pulse signals.
 4. The encoder signal processingdevice according to claim 1, wherein the pulse signal detection unitdetects only initial one pulse signal within the effective detectionperiod.
 5. The encoder signal processing device according to claim 2,wherein the pulse signal detection unit detects only initial one pulsesignal within the effective detection period.
 6. The encoder signalprocessing device according to claim 3, wherein the pulse signaldetection unit detects only initial one pulse signal within theeffective detection period.
 7. The encoder signal processing deviceaccording to claim 1, further comprising: a delay circuit that outputsthe pulse signal detected by the pulse signal detection unit by delayingthe pulse signal by a certain time period.
 8. The encoder signalprocessing device according to claim 2, further comprising: a delaycircuit that outputs the pulse signal detected by the pulse signaldetection unit by delaying the pulse signal by a certain time period. 9.The encoder signal processing device according to claim 3, furthercomprising: a delay circuit that outputs the pulse signal detected bythe pulse signal detection unit by delaying the pulse signal by acertain time period.
 10. The encoder signal processing device accordingto claim 4, further comprising: a delay circuit that outputs the pulsesignal detected by the pulse signal detection unit by delaying the pulsesignal by a certain time period.
 11. The encoder signal processingdevice according to claim 5, further comprising: a delay circuit thatoutputs the pulse signal detected by the pulse signal detection unit bydelaying the pulse signal by a certain time period.
 12. The encodersignal processing device according to claim 6, further comprising: adelay circuit that outputs the pulse signal detected by the pulse signaldetection unit by delaying the pulse signal by a certain time period.13. The encoder signal processing device according to claim 7, whereinthe certain time period is a time period that corresponds to theeffective detection period.
 14. A printer comprising: the encoder signalprocessing device according to claim 1; an image data input unit thatinputs image data; a line head that is driven based on the input imagedata; a transport unit that transports a printing medium as thetransported body in a direction orthogonal to a longitudinal directionof the line head; the encoder that outputs the encoder signal includinga pulse signal having a cycle corresponding to a transport speed of theprinting medium transported by the transport unit; and a control unitthat controls a printing timing of the line head for a line image insynchronization with the pulse signal detected by the pulse signaldetection unit and the pulse signal generated by the pulse signalgeneration unit.
 15. The printer according to claim 14, wherein theeffective detection period setting unit sets the effective detectionperiod based on a cycle of the pulse signal acquired from a plurality ofthe pulse signals detected by the pulse signal detection unit before theprinting timing of the line head for the line image and a width ofchange in the transport speed of the printing medium.
 16. The printeraccording to claim 15, wherein the plurality of pulse signals before theprinting timing are three or more pulse signals, and the cycle of thepulse signal is a cycle of an average of two or more cycles acquiredfrom the three or more pulse signals.
 17. The printer according to claim14, wherein the transport unit includes a capstan roller and a pinchroller that pinch and transport the printing medium, and the encoder isa rotary encoder that includes a circular plate arranged coaxially withan axis of the capstan roller and outputs the encoder signal including apulse signal having a cycle corresponding to a rotational speed of thecircular plate.
 18. The printer according to claim 14, wherein theprinting medium is an instant film that senses light depending on anamount of light, and the control unit controls an amount of lightemission emitted from the line head based on the input image data andcauses the instant film to sense light.
 19. A printer-equipped imagingapparatus comprising: the printer according to claim 14; and an imagingunit that functions as the image data input unit.
 20. An encoder signalprocessing method comprising: a step of inputting an encoder signalincluding a pulse signal having a cycle corresponding to a transportspeed of a transported body from an encoder detecting the transportspeed of the transported body; a step of setting an effective detectionperiod for detecting a subsequent pulse signal each time the pulsesignal is detected from the input encoder signal; a step of detectingthe pulse signal from the encoder signal only within the set effectivedetection period; and a step of generating the pulse signal after theeffective detection period in a case where the pulse signal is notdetected from the encoder signal within the effective detection period.